ABSTRACT
The eye globe is housed in a bony socket, the orbit, which has a bony posterior wall, superior, medial and lateral walls, but with its anterior aspect protected by the upper and lower eyelids. The function of the eyelids first and foremost is to protect the eye from noxious physical stimuli including light, heat, cold and debris. The eyelids fulfil these functions by a series of reflex responses initiated by stimulation of nerve endings in the ocular surface and by light sensitivity mediated through the retina (Figure 3, page 8).
